Antioffset mechanism for printing presses



Feb. 27, 1934. R. J. GREENWAY ANTIOFFSET MECHANISM FOR PRINTING`PRESSS Filed Sept. 24, 1931.

` INVENTOR ATTORNEYS Patented Feb. 27, 1934 UNITED s'rATEs PATENT OFFICE Richard J. Greenway, Westerly, R. I., assignor to C. B. Cottrell & Sons Company, Westerly, RJ., a corporation of Delaware Application September 24, 1931 Serial No. 564,771

6 claims.

The object of my invention is to provide certain improvements in the construction, form and arrangement of the several parts of the antioifset mechanism whereby a uniform and minig mum amount of anti-offset powder can be applied to the freshly printed side of a sheet or web. A practical embodiment of my invention is represented in the accompanying drawing in which:

proved anti-offset mechanism;

Fig. 2 represents a detail longitudinal section taken in the planes of the lines II-II of Fig. 1;:

Fig. 3 represents a detail section taken in the plane of the line III-111 of Fig. 2; and

Fig. 4 represents a detail section of a modified form of web contacting roll and powder transfer roll.

The freshly printed web 1 is shown as passing from the plate and impression cylinders 2, 3. to and around a reel 4, which reel may be positively driven from the impression cylinder gear 5 through the train of gears 6, 'l and 8.

The anti-onset powder supply fountain is denoted by 9 and the fountain roll by 10. An adinstable doctor knife 11 is mounted in the fountain in position to regulate the amount of antioffset powder taken by the fountain roll 10. The web contacting roll which applies the anti-offset vpowder to the freshly printed face of the web 1 is denoted by 12 and it may be positively driven from the gear '7 through the gear 13. The fountain roll 10 may be positively driven from the web contacting roll 12, as, for instance,.by a chain and sprocket connection 14 and 15, 16.

The anti-offset powder transfer roll 17 is mounted in position to transfer the anti-offset powder from the fountain roll l0 to the web con- 4.0 tacting roll 12. This transfer roll 17 is provided with means 18 for adjusting the roll into greater or lesser contact with the fountain roll 10 and web contacting roll 12 to transfer more or less antioffset powder from the roll 10 to the roll l2.

The web contacting roll 12 may be made entirely of soapstone as shown in Fig. 3, or it may.

be provided withk a web contacting surface of soapstone as shown in Fig. 4. Alsothe transfer roll 17 may be made of felt as shown in Fig. 3, or

v it may have a covering of felt, pile fabric or the like as shown in Fig. 4'.

I have found that by providing the web contact surface of the web contacting roll 12 of soapstone I am enabled to secure a very uniform and minimum application of the anti-offset powder to Fig. 1 represents in side elevation so much of al web printing rotary press as includes my nnthe freshly printed face of the web, the soapstone surface of the web contacting roll preventing absolutely the caking of the anti-offset powder thereon.

It is evident that various changes may be re- 30 sorted to in the construction, form and arrangement of the several parts without departing from the spirit and scope of my invention. and hence I do not intend to be limited to the particular embodiment herein shown and described, but

1. An anti-offset mechanism comprising an anti-offset powder supply fountain, a fountain roll, a web contacting roll for applying the antioffset powder to the freshly printed face of a 7o web, and an anti-offset powder -transfer roll for transferring the anti-offset powder from the fountain roll to the web contacting roll, the web contacting roll having its web contacting surface of soapstone.

2. An anti-offset mechanism comprising an anti-offset powder supply fountain, a fountain roll, a web contacting roll for'applying the antioiset powder to the freshly printed face of a web, and an anti-offset powder transfer roll for so transferring the anti-offset powder from the fountain roll to the web contacting roll, the web contacting roll being of soapstone.

3. An anti-offset mechanism comprising an anti-offset powder supply fountain, a fountain B5 roll, a web contacting roll for applying the antioffset powder to the freshly printed face of a web, and an anti-offset powder transfer roll for transferring the anti-offset powder from the A fountain roll to the web contacting roll, the transfer roll having its contact surface of textile fabric, and the web contacting roll having its web contacting surface of soapstone.

4. An anti-offset mechanism comprising an anti-offset powder supply fountain, a fountain roll, a web contacting roll for applying the antioffset powder to the freshly printed face of a web, and an anti-offset powder transfer roll for transferring the anti-offset powder from the fountain roll to the web contacting roll, the transfer roll having its contact surface of textile fabric, and the web 4contacting roll being of soapstone.

5. An anti-offset mechanism comprising an los anti-offset powder supply fountain, a fountain roll, a web contacting roll for applying the antioifset powder to the freshly printed face of a web, and an anti-offset powder transfer roll for transferring the anti-offset powder from the no' web, and an anti-o`set powder transfer Jog transferring the ant-oset powder imm the fountain roll to the web. contacting rail, the transfer roll being of felt, and the web contacting roll being of soapstone.

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